How to make a blooming bath oil in 10 minutes (no experience needed)

Updated: 09.03.26

Did you know that most bath oils on the market are simply blends of carrier oils with large amounts of essential oils floating on top?

This means the essential oils aren’t properly dispersed, which can irritate your skin or even cause long-term sensitisation. That’s because essential oils are incredibly potent ingredients, and when used incorrectly, they can do more harm than good.

So does that mean you have to stop using bath oils altogether?

Luckily, no – because there’s a better way. You can make your own skin-safe bath oil, and in this post, we’ll show you exactly how.

And the best part? You can make it in just 10 minutes!

What makes this bath oil so special

This bath oil is skin-friendly and suitable for all skin types thanks to nourishing plant oils like castor oil and plum oil. But what makes it truly special is its magical, transforming texture.

The moment this bath oil touches water, it turns into a silky milk, creating a luxurious soak that feels like an indulgent spa treatment. It looks beautiful, smells incredible (imagine a flower bouquet in your bath), and also makes a great, thoughtful handmade gift.

Its vibrant red colour comes from a special plant extract that naturally transforms the oil into a striking cherry-red shade – but more on this secret ingredient later!

What you’ll need to make this bath oil

Here’s everything you need to make this blooming bath oil.

You don’t need fancy equipment or a lab setup to make this – just a clean workspace and a few basic tools you probably already have in your kitchen, or can find online or in kitchenware shops.

All ingredients are widely available and easy to source, and we’ve also included a handy supplier list at the end of this post!

Equipment

You will need:

• Scales for accurate measurements – these are super easy to find and cost about $10 on Amazon
• A glass beaker or any other mixing container
• A glass rod or spoon for gentle stirring
• Pipettes (optional) to precisely add your ingredients, but you could also just carefully pour and weigh your ingredients if you don’t have any on hand.
• Gloves and an apron for safety and hygiene
• And a suitable container for storing your bath oil (we used a 250ml glass bottle, but you could also use aluminium or PET plastic)

You can find all of this equipment listed on our Amazon storefront.

And that’s it! Before you start, you’ll also need to wash your hands, tie your hair back if you have long hair, and clear a bit of counter space.

Ingredients

And now for the ingredients! To make 250 grams of this blooming bath oil, you will need:

87g castor oil

80g fractionated coconut oil (MCT oil)

50g Polyglyceryl-4 Oleate (more on this ingredient in the breakdown section below)

25g plum oil

2.5g bergamot essential oil

1.25g lavender essential oil

1.25 ylang ylang essential oil

2.5g vitamin E

And lastly, 0.50g of gromwell extract (the secret ingredient!)

You can also find a full ingredient breakdown in the section below.

Ingredient breakdown

You only need 7 ingredients to make this gorgeous bath oil.

These are either natural or naturally-derived ingredients (more on the definition of natural in cosmetics here), widely available, and easy to source.

1. Castor oil

INCI: Ricinus Communis Seed Oil

First up, you’ll need 87 grams of castor oil.

This oil is a thick, glossy, and almost syrupy liquid. It’s commonly used in lip gloss formulations because of its shine and cushioning feel.

In this bath oil, it provides deep conditioning benefits, leaving your skin feeling soft and nourished after soaking.

Interested to learn more about castor oil? Then check out this post about the benefits of castor oil!

2. Fractionated coconut oil (MCT oil)

INCI: Caprylic/Capric Triglyceride

Then, you’ll need 80 grams of fractionated coconut oil (aka MCT oil).

Fractionated coconut oil is simply a fraction of coconut oil that’s been refined to keep only the lightest, silkiest part.

This makes it beautifully clear, fast-absorbing and non-greasy. MCT oil also helps balance out the richness of castor oil, so your skin feels soft and moisturised after the bath without any oily residue – and makes your bath oil feel like a luxurious, professional-grade product.

3. PGMO.4

INCI: Polyglyceryl-4 Oleate

And now for the magic ingredient that turns your bath oil into a silky milk the moment it hits water!

You’ll need 50 grams of PGMO.4, aka Polyglyceryl-4 Oleate. This is an emulsifier – a special ingredient that helps oils and water mix together, creating a luscious, milky texture.

While the name might sound “chemical,” it’s actually derived from plant oils and glycerine. It’s gentle, skin-friendly, and completely safe.

You can find it from specialist cosmetic ingredient suppliers worldwide in small quantities, and we’ve also included a few recommended suppliers at the bottom of this post.

Since PGMO.4 is quite thick, you’ll need to pour it carefully into your mixing beaker or bowl.

4. Plum oil

INCI: Prunus Domestica Seed Oil

You’ll also need 25 grams of plum oil – a gorgeous, light golden oil that gives this bath oil a beautiful, silky texture.

This fruit oil also has a subtle natural marzipan scent, adding a delicate sweetness and creating a wonderfully indulgent aroma for your bath.

5. Bergamot, lavender & ylang-ylang essential oils

INCI: Citrus Aurantium Bergamia Peel Oil/Lavandula Angustifolia Oil/Cananga Odorata Flower Oil

You will also need some essential oils to give this bath oil its luxurious, calming, floral scent. We’ve chosen:

• 2.50 grams of bergamot essential oil, which has a lovely earthy citrus fragrance
• 1.25 grams of lavender essential oil, which adds a calming and floral note
• 1.25 grams of ylang-ylang essential oil, which contributes to a rich, sweet, and floral aroma

Now, we realise that we said earlier that essential oils can sometimes irritate the skin in bath oils – but that usually happens when they aren’t properly dispersed and consequently float on the surface of the water.

But in this case, the Polyglyceryl-4 Oleate helps the essential oils disperse evenly throughout the formula and bathwater, instead of sitting on top, making the bath oil skin-safe.

6. Vitamin E

INCI: Tocopherol

You will also need 2.50 grams of vitamin E, a powerful antioxidant which helps protect your plant oils from oxidation and extend the shelf life of your bath oil, keeping it fresh for longer.

This well-known vitamin also has skin-conditioning properties, leaving your skin feeling nourished and soft after your bath.

7. Gromwell extract

INCI: Helianthus Annuus Hybrid Oil, Simmondsia Chinensis Seed Oil, Lithospermum Erythrorhizon Root Extract

And now for the secret last ingredient! You will need 0.50 grams of gromwell extract. This extract comes from a remarkable plant that has been cultivated in Japan for over 1,000 years, where it was traditionally used for herbal medicine and natural dyes.

Gromwell extract gives your bath oil a striking cherry-red colour that looks stunning both in the bottle and in the bath. Just be careful when using it, as it can stain surfaces, and make sure you wear gloves to avoid red fingers!

But don’t worry – once it’s mixed into your bath oil, it won’t stain your skin.

Now, gromwell extract is a bit of a specialist ingredient, so it might not be easy to get where you live.

If you can’t find it, you can absolutely leave it out, or swap it for other plant-based colourants like blue tansy essential oil, sea buckthorn oil, or buriti fruit oil, all of which will also give your bath oil a lovely colour.

We cover alternative plant-based colourants in this post.

How to make a skin-safe blooming bath oil (no experience needed)

• Makes: 250g
• Time: 10-15 minutes
• Level: Beginner-friendly

Step-by-step method:

Here’s how to make this bath oil in 4 simple steps:

• Step 1: Weigh your castor oil, fractionated coconut oil, Polyglyceryl-4 Oleate and plum oil

Start by weighing your base ingredients in a clean beaker or bowl. You’ll need 87 grams of castor oil, 80 grams of fractionated coconut oil, 50 grams of Polyglyceryl-4 Oleate, and 25 grams of plum oil.

Don’t forget to tare your scale after each addition to reset the scale by pressing the ‘tare’ button.

• Step 2: Add your essential oils

Next, add your essential oils, one by one, taring the scale after you add each one.

That’s 2.50 grams of bergamot essential oil, 1.25 grams of lavender essential oil, and 1.25 grams of ylang-ylang essential oil.

• Step 3: Add your vitamin E and gromwell extract and stir

It’s now time to add 2.50 grams of vitamin E and 0.50 grams of gromwell extract – your showstopper ingredient.

Mix all the ingredients together using a clean glass rod or spoon, and watch as your golden mix transforms into a rich, vivid red colour, and a glossy, vibrant, and luxurious bath oil. This is truly one of the most satisfying parts of the whole process.

• Step 4: Transfer to a bottle & label

And now for the final step! Pour your mixture into its final container. We’ve used a transparent curved-glass apothecary bottle, but use whatever you want!

All that’s left to do now is to label your bath oil with the name and date, and it’s ready to use!

Why not try customising your bath oil by experimenting with different plant oils, essential oils or natural colourants? We cover different options for you in this post about natural plant colourants. Just make sure you respect the original quantities, as this formula has been carefully designed to work at these amounts. This is especially important when trying different essential oils.

How to use your bath oil

To use your bath oil, pour a small amount into your bathwater and watch your clear red oil transform into an indulgent, silky, milky soak (aka the ‘blooming’ effect). Your bathwater will take on a soft colour without staining skin or leaving greasy residue.

And because the oils are properly dispersed, there will be no oily layer floating on top, making this blooming bath oil completely skin-friendly and safe!

All that’s left to do is relax and enjoy soft, conditioned skin!

Want to make more skincare?

We hope you enjoyed this post and feel inspired to make – and try – this blooming bath oil yourself! You can also follow along with the YouTube video embedded in this post to watch the full process step by step.

Once you see just how easy and satisfying it is to make your own bath oil, you’ll probably start wondering what other skincare and bodycare products you can create.

So if you enjoyed this and want to take things further, why not join our free short formulation course?

It’s the perfect next step to start building real formulation skills and confidence, learn how skincare products are truly made, and start creating your own natural skincare and bodycare products from scratch.

Suggested suppliers

Here is a list of reputable suppliers you can use to source the ingredients for this bath oil:

INKY Ingredients (UK)

Aroma-Zone (EU)

Aromantic (UK)

Alexmo Cosmetics (EU)

Manske (EU)

The Soap Kitchen (UK)

Ellemental  (EU)

Lotioncrafter (USA)

Essential Labs (USA)

Go Native NZ (New Zealand)

Naturally Balmy (UK)

O&3 – The Oil Family (UK/EU)

Soap & More (Canada)

Handymade (EU)

Formulator Sample Shop (USA)

Personally, we sourced the PGMO.4 from Alexmo, but you could also use Durosoft PG4-O from Bay House Aromatics, or find another version from a different supplier. For the gromwell extract, we sourced ours from Aroma Zone (where it’s called Rouge Grenadine), but you can also find it on Dauphine Organics.

Bear in mind that while the INCI name (the cosmetic ingredient name) is usually the same for the listed ingredients, there may be slight differences between products depending on the supplier.

FAQ

• What is a bath oil?

A bath oil is a lovely addition to your bathtime routine, designed to nourish and moisturise your skin while creating a relaxing sensory experience.

This particular bath oil stands out thanks to its transforming texture, turning from an oil blend into a milky solution when it hits water. Its beautiful red colour and soothing floral scent also make it perfect for gifting (or keeping to yourself!)

• How do you use this bath oil?

Add your desired amount to warm running bathwater. The oil will disperse into a silky milky solution and won’t leave an oily residue in the tub – so you don’t have to worry about greasy residue on your skin or extra clean-up!

• What does this bath oil look like, feel like, and smell like?

It is a slightly viscous cherry-red liquid with a soft floral scent of bergamot, lavender, and ylang-ylang. In water, it becomes a lightweight milky soak that leaves skin soft and conditioned.

• How can you customise this bath oil?

This formulation is fully customisable, so you can experiment with different plant oils, essential oils, or natural colourants. Just make sure you keep the same overall ratios.

Since this is a rinse-off product, avoid using expensive ingredients, as they will literally go down the drain. Simply experiment and have fun!

Leave us a comment

comments

Beatriz Amaral

Beatriz Amaral, a cosmetic scientist worked at Formula Botanica from 2021 – 2025. Read more about the Formula Botanica team.